This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A202745 #8 Jul 22 2025 16:49:06 %S A202745 2,10,86,838,6870,62398,613950,6018166,59293518,601267870,6215708078, %T A202745 64727555230,679456522670,7200537529326,76879249259246, %U A202745 825573117666246,8913831877350462,96733061472889806,1054372579551732366 %N A202745 Number of 4Xn 0..1 arrays with row sums equal and column sums unequal to adjacent columns. %C A202745 Row 4 of A202742 %e A202745 Some solutions for n=5 %e A202745 ..1..1..0..0..1....0..1..0..0..1....1..1..0..1..0....1..0..0..1..0 %e A202745 ..0..1..0..1..1....0..1..0..0..1....1..1..0..0..1....1..1..0..0..0 %e A202745 ..0..1..1..1..0....0..1..0..0..1....1..1..0..1..0....1..0..0..0..1 %e A202745 ..1..1..0..1..0....0..0..0..1..1....1..0..0..1..1....1..0..0..1..0 %K A202745 nonn %O A202745 1,1 %A A202745 _R. H. Hardin_ Dec 23 2011